Hi, newbie here! I saw a movie, only part of it remains with me. 1970's movie, all I can remember is that people are survivors of something, and they come back home to find everyone has dissolved into salt? Their clothes are where they stood or laid and there is some sort of powder/salt where their body was. Help?

If the powder left behind by the dissolved people was white, like salt, I agree that this is probably "Where Have All the People Gone." The timeframe (1970s) also fits better than "Night of the Comet."